Light powers faster 3D printing

Jan. 11 (UPI) -- Scientists have developed a new technique for faster, more efficient 3D printing. Instead of building objects layer by layer, the new method uses light to solidify 3D shapes from a vat of liquid.

Traditional 3D printing methods don't make sense for small-batch manufacturing jobs with a quick turnaround time.

The new technique, which uses a pair of light beams to control which bits of liquid resin become solidified and which remain in fluid form, could allow manufacturers to turn around small batch projects in a couple of weeks.

Whereas traditional 3D printers build three dimensional objects using additive techniques, combining 1D lines or 2D cross sections, bit by bit, the new device relies on a phase change to build a 3D object with a single shot.

"It's one of the first true 3D printers ever made," Mark Burns, professor of chemical engineering and biomedical engineering at the University of Michigan, said in a news release.

Previous attempts to solidify objects in a vat of liquid were held up by various technical hurdles. Early models were foiled by solidifying resin on the window through which the light penetrated. As quickly as the printing process began, it stopped, the light thwarted by a wall of solidified resin.

Researchers attempted a variety of workarounds, but each new attempt faced new difficulties. The latest method solves the window problem by deploying a second light beam designed to prevent resin near the vat window from solidifying.

The resin features both photoactivator and photoinhibitor additives, which react to different light wavelengths to trigger either solidification or liquefaction.

The double beam technique allows the object to form within a large region of liquid resin, freeing up researchers to use thicker, more viscous resins reinforced with powdered additives.

"You can get much tougher, much more wear-resistant materials," said Timothy Scott, associate professor of chemical engineering at Michigan.

Researchers described their novel technique this week in the journal Science Advances.